fix group layer handling

we don't want to accidentally copy maps, whoopsie

lib/CheckMap.hs

@@ -105,15 +105,17 @@ runLinter config tiledmap depth = MapResult
     checkThing getter checker = V.toList . V.map runCheck $ getter tiledmap
       where runCheck thing = runLintWriter config thing depth checker
 
-
     -- | "inverts" a LintResult, i.e. groups it by lints instead of
     --    layers / maps
     invertThing thing = M.unionsWith (<>) $ fmap invertLintResult thing
 
-
     adjustedMap = (resultToAdjusted generalResult)
-      { tiledmapLayers = V.fromList $ fmap resultToAdjusted layer
-      , tiledmapTilesets = V.fromList . fmap resultToAdjusted $ tileset
+      { tiledmapLayers = V.fromList
+          . fmap resultToAdjusted
+          $ take (length (tiledmapLayers tiledmap)) layer
+      , tiledmapTilesets = V.fromList
+          . fmap resultToAdjusted
+          $ tileset
       }
 
 -- | Recursively checks a layer.
@@ -121,15 +123,26 @@ runLinter config tiledmap depth = MapResult
 -- This is apparently necessary because someone thought it would be a good
 -- idea to have group layers, even if their entire semantics appear to be
 -- "they're group layers"; they don't seem to /do/ anything …
+--
+-- Note that this will flatten the layer structure and give them all back
+-- in a single list, but the ones that were passed in will always be at
+-- the head of the list.
 checkLayerRec :: LintConfig' -> Int -> [Layer] -> [LintResult Layer]
-checkLayerRec config depth = concatMap $ \parent ->
+checkLayerRec config depth layers =
+  -- reordering to get the correct ones back up front
+  (\rs -> fmap fst rs <> concatMap snd rs)
+  -- map over all input layers
+  $ flip fmap layers $ \parent ->
   case layerLayers parent of
+    -- not a group layer; just lint this one
     Nothing ->
-      [runLintWriter config parent depth checkLayer]
+      (runLintWriter config parent depth checkLayer,[])
+    -- this is a group layer. Fun!
     Just sublayers ->
       let
         -- before linting, append the group's top-level name to that of sublayers
-        results = checkLayerRec config depth $ sublayers
+        results = take (length sublayers)
+                  $ checkLayerRec config depth $ sublayers
                   <&> \l -> l { layerName = layerName parent <> "/" <> layerName l }
         -- get the original sublayer names
         names = fmap layerName sublayers
@@ -141,7 +154,7 @@ checkLayerRec config depth = concatMap $ \parent ->
                      names results
                    }
             ) depth checkLayer
-      in result:results
+      in (result,results)